gbk' codec can't decode byte 0x80 in position 306: illegal multibyte sequence

This error message indicates that the "gbk" codec (a Chinese character encoding) is unable to decode a byte at position 306 in a given string because it is an illegal multibyte sequence. This could occur for a variety of reasons, such as the string containing invalid or corrupted data, or the encoding being incorrect. To resolve this error, you may need to check the source of the string and ensure that it is properly encoded or try decoding it using a different codec.